These 'folks you know' who were arrested for DUI despite blowing under the limit would have been immediately found not guilty in court. Not to mention the LEO looking, to the judge and the public, like even more of a fool than usual. Not to mention exposing him/her/selves and their jurisdiction to suit for improper prosecution. Makes you wonder why he/she would make such an arrest, especially more than once!
They were arrested, not convicted. As soon as they (very wisely) lawyered up, charges were dropped in both cases. Still had to pay court fees and the lawyer's retainer, though...and one guy had his car towed while he was being hauled off to jail, and had to pay the fee to get it back from the impound lot.
Both were college age men driving alone late on weekend evenings, and got caught in DUI checkpoints run by local police, not state troopers. The two incidents were in different towns, several months apart.
I wouldn't believe it either if it hadn't happened to two friends of mine! I wouldn't expect it from state troopers, but some town cops are a different story...